unknown snail hitchhikers

hi- the other night i noticed several tiny black snails with whit markings on them and have been unable to identify them. they are cone/trumpet shaped(just noticed another larger one, about 1/4"-1/3" long) and about 3/16" long. the 'head' area has broader white stripes, and the lower 2/3s are more like a checkerboard pattern. any ideas? i'll see if i can get a picture to post, but with the camera i have this may be an endeaver.

Mark

regarding snail pic...

No they do not look like this. although I have seen one of these, but not in a while-will remove ASAP as soon as i see it again (unless the bluelegs took care of it-they semm to have done a number on several of my snails.
The ones I am describing are more like a unicorns horn in shape,
I am working nights right now, so will be unable to try and get photos until I'm off as they are nocturnal, or at least seem to disappear when the lights are on. I'll keep you posted, and e-mail you when i get a photo or find an ID. (regarding your photo-the one I saw was very tiny, and was on the rock that has my yellow zoanthids, so I am now on a Search & Destry mission for these that you posted the pic of.

Thanks OrionGirl,
Mark